两个精制电阻,用锰铜电阻丝绕制而成,电阻上分别标有“100Ω,10W”和“20Ω,40W”,则它们的额定电流之比为( )
A:5 :5
B:10 :20
C:5 :10
D:1:2 000
看图,配对,将句子编号写在相应的横线上。
A. The pears are juicy and sweet. Here you are.
B. - How is the juice? - It's very sweet.
C. Smell the soup. It's very nice.
D. - How is the rice, Peter? - It's yummy.
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